Think of maps as promises to your readers that help establish their expectations and convey your purpose for writing. If you are working on an informative document, you might promise to explain the details of a complex issue to your readers. If you define a problem in your introduction, that definition serves as a promise to present a solution by the end of your document. If you begin with a surprising argument, you are promising to back it up with reasons and evidence that will intrigue your readers.

Making a promise in a written document differs pleasantly from making a promise in person, because in writing you haven’t really promised it until you submit your final draft. As you draft and revise your document, keep your eyes open for unfulfilled promises. Depending on how your argument has developed as you’ve drafted your document, you might find that you no longer need to follow through on your promise. If so, take it out. If you still need it, be sure to include it.